A die for processing plastically moldable material, especially a synthetic resin or plastic, can have a circularly cylindrical cross-section passage provided in a wall of the die which opens onto an embossing surface of the die.
A rotatable cylindrical marking device which can be held fixed in a particular rotational position is inserted in this cylindrical passage in the die. The front surface of this marking device forming part of the embossing surface of the die has at least one mark which correlates with at least one stationary marking on an adjoining part of the embossing surface.
An injection molding or pressing die for this purpose has an adjustable cylindrical circular cross-section device mounted flush with the embossing surface for applying different marks to the product of the die. The front surface of this known marking device is provided as part of the embossing surface of the die with one or more marks, which are either raised from or recessed in that front surface. For example, these marks can comprise month-indicating characters. The adjoining embossing surface of the die is provided in the immediate vicinity of the front surface of the marking device with a reference marking, which is reproduced in the article formed as a product by the die as a dashed line or line-type raised or depressed marking.
The known marking device is made for the special case of injection molding or pressing dies and of course is inserted in a wall of the die.